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31 votes
31 votes
Solve 5/(r-9)=8/(r+5)

User Arijeet Saha
by
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2 Answers

18 votes
18 votes

Answer:

r = 32 1/3 or 97/3

Explanation:

Step 1: Cross-multiply.


  • 5*(r+5)=8*(r-9)

  • 5r + 25 = 8r - 72

Step 2: Subtract 8r from both sides.


  • 5r + 25 - 8r = 8r - 72 - 8r

  • -3r +25=-72

Step 3: Subtract 25 from both sides.


  • -3r + 25 - 25 = -72 - 25

  • -3r = -97

Step 4: Divide both sides by -3.


  • (-3r)/(-3)=(-97)/(-3)

  • r=(97)/(3)

  • r = 32(1)/(3)

Therefore, r = 32 1/3 or 97/3.

User Dviljoen
by
3.5k points
14 votes
14 votes

Answer:

r = 32 1/3

Explanation:

5/(r-9) = 8/(r+5)

cross multiply:

5 x (r + 5) = 8 x ( r - 9)

5r + 25 = 8r - 72

Add 72 to both sides:

5r + 97 = 8r

Subtract 5r from both sides

97 = 3r

Divide both sides by 3

r = 32 1/3

-Chetan K

User Ravi Limbani
by
3.1k points